Messages in this thread Patch in this message | | | From | Bart Van Assche <> | Subject | [PATCH v2 1/3] configfs: Restore the kernel v5.13 text attribute write behavior | Date | Wed, 28 Jul 2021 21:41:23 -0700 |
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Instead of appending new text attribute data at the offset specified by the write() system call, only pass the newly written data to the .store() callback.
Cc: Bodo Stroesser <bostroesser@gmail.com> Cc: Martin K. Petersen <martin.petersen@oracle.com> Cc: Yanko Kaneti <yaneti@declera.com> Cc: Brendan Higgins <brendanhiggins@google.com> Reported-by: Bodo Stroesser <bostroesser@gmail.com> Tested-by: Bodo Stroesser <bostroesser@gmail.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- fs/configfs/file.c | 18 ++++++------------ 1 file changed, 6 insertions(+), 12 deletions(-)
diff --git a/fs/configfs/file.c b/fs/configfs/file.c index 5a0be9985bae..0ad32150611e 100644 --- a/fs/configfs/file.c +++ b/fs/configfs/file.c @@ -177,28 +177,22 @@ static ssize_t configfs_bin_read_iter(struct kiocb *iocb, struct iov_iter *to) return retval; } -/* Fill [buffer, buffer + pos) with data coming from @from. */ -static int fill_write_buffer(struct configfs_buffer *buffer, loff_t pos, +/* Fill @buffer with data coming from @from. */ +static int fill_write_buffer(struct configfs_buffer *buffer, struct iov_iter *from) { - loff_t to_copy; int copied; - u8 *to; if (!buffer->page) buffer->page = (char *)__get_free_pages(GFP_KERNEL, 0); if (!buffer->page) return -ENOMEM; - to_copy = SIMPLE_ATTR_SIZE - 1 - pos; - if (to_copy <= 0) - return 0; - to = buffer->page + pos; - copied = copy_from_iter(to, to_copy, from); + copied = copy_from_iter(buffer->page, SIMPLE_ATTR_SIZE - 1, from); buffer->needs_read_fill = 1; /* if buf is assumed to contain a string, terminate it by \0, * so e.g. sscanf() can scan the string easily */ - to[copied] = 0; + buffer->page[copied] = 0; return copied ? : -EFAULT; } @@ -227,10 +221,10 @@ static ssize_t configfs_write_iter(struct kiocb *iocb, struct iov_iter *from) { struct file *file = iocb->ki_filp; struct configfs_buffer *buffer = file->private_data; - ssize_t len; + int len; mutex_lock(&buffer->mutex); - len = fill_write_buffer(buffer, iocb->ki_pos, from); + len = fill_write_buffer(buffer, from); if (len > 0) len = flush_write_buffer(file, buffer, len); if (len > 0)
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